Device for soundless reversing of the carriages of typewriters



July 20 {1926. 1,592,960

' G. PERSSON DEVICE FOR SOUNDLESS REVERSING OFTHE CARRIAGES or TYPEWRITERS Filed Jan .23, 1926 Patented July 20, 1926.

GOTTFRII) PERSSON, OF SVANGSTA, SWEDEN.

DEVICE FOR SOUNDLESS BEVERSING OF THE GARRIAGES 0F TYPEWRITERS.

Application filed January 28, 1926, Serial No. 84,445, and. in Sweden January 12, 1925.

In most of the typewriters an objectionable ratching noise is produced when the carriage is reversed. This is due to the fact that the teeth of the escapement one after the other contact against the spring actuated pawl which checks the movement of the escapement.

The object of the invention is to eliminate the said noise, which is effected by automatically bringing the pawl by means of a special attachment out of the path of move ment of the escapement when the carriage is reversed. This attachment is, contrary to hitherto known constructions, entirely free and independent of the escapement itself.

The invention in the preferred form of details is illustrated in the accompanying drawings, wherein only such elements of a typewriter are shown which are essential for the invention.

In the drawing: Fig. 1 is a rear elevational view of a typewriter, showing the parts in the position when the carriage is travelling in the usual way, that is the automatic release device is in inoperative position, a portion of the frame of the typewriter being broken away. Fig. 2 is a similar view but showing the automatic release device in operative position, the carriage being operated in reverse direction. Figs. 3 and 4 are a lateral view and a front view respectively of the special attachment disconnected.

Smilar numerals of reference denote corresponding parts throughout the several views.

Referring to Fig. 1 the toothed rack 1 of the carriage (not shown) is in engagement with a pinion 2 fixed to the axle 3 carrying the escapement 4 and also in engagement with a pinion 5 attached to the pivoted releasing lever 6. The toothed rack 1 is fed step by step in a manner known per se in the direction of the arrow'7 when the typewriter is operative. the escapement 4 being alternately released from engagement with the pawl 8 and checked in its movement by the latter. The pinion 5 is freely rotatable on a pin fixed to the lever 6, and between the pinion and the lever a helical spring 9 (see Fig. 3) is wound round said pin in such a manner that the pinion 5 rotates with a certain amount of friction which is considerably greater than the friction of the pivot of the lever 6. On account of the friction which influences the free rotation of the pinion 5 the toothed rack 1 when it is moved carries the latter and the lever 6 in the direction of the arrow 7, until the lever abuts against a stop 10, so that the lower free end of the lever 6 is kept out of engagement with a projecting arm of the pawl 8, as shown in Fig. 1.

Fig. 2 shows the releasing device in operative position. When the carriage of the typewriter together with its toothed rack 1 is reversed, that is in the direction of the arrow 11, the pinion 5 on account of the friction due to the spring 9 is carried by the rack in the direction of the arrowll and thus the lever 6 will rock about its pivot, until it abuts against the stop 12. The lever 6 is bent at a right angle at its lower end forming the part 13 which cooperates with the projecting arm 14 of the pawl 8 and turns the latter about its pivot 15. By this movement the pawl 8 is brought out of engagement with the escapement 4: and is kept in this position as long as the toothed rack 1 is moved in the direction of the arrow 11. Thus the escapement is rendered to rotate freely and the objectionable noise produced by the repeated contact of the same with the pawl when the carriage is reversed, is completely avoided.

What I claim is 1. In a typewriter of the type specified the provision of a rocking lever provided with a pinion in constant engagement with the toothed rack of the carriage, the other free end of said lever adapted to engage an arm projecting from the pawl when the carriage is reversed. Y

2. In a typewriter of the type specified the provision of a rocking lever, a pin on the one end of the lever, a pinion mounted freely rotatably on said pin, a. friction producing helical spring arranged between the pinion and the lever, the other end of the lever bent at right angles, said bent end adapted to actuate an arm projecting from the pawl when the lever is rocked in the one direction.

3. In a typewriter of the type specified capement provided with a projecting arm the provision of a rocking double-armed learranged in the path of the other end of the ver having at the one end a freely rotatable rocking lever. 10

pinion Which is checked in its rotation by In testimony whereof I have signed my 5 friction means and is in constant engagename to this specification.

ment with the toothed rack of the carriage,

the pawl checking the movement of the es- 7 GOTTFRID PERSSON. 

